================================================================== BUG: KASAN: use-after-free in test_bit include/asm-generic/bitops-instrumented.h:237 [inline] BUG: KASAN: use-after-free in tty_port_kopened include/linux/tty.h:673 [inline] BUG: KASAN: use-after-free in tty_open_by_driver drivers/tty/tty_io.c:1964 [inline] BUG: KASAN: use-after-free in tty_open+0x6f8/0xbb0 drivers/tty/tty_io.c:2033 Read of size 8 at addr ffff8880a7e49200 by task syz-executor641/8951 CPU: 0 PID: 8951 Comm: syz-executor641 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:638 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:94 test_bit include/asm-generic/bitops-instrumented.h:237 [inline] tty_port_kopened include/linux/tty.h:673 [inline] tty_open_by_driver drivers/tty/tty_io.c:1964 [inline] tty_open+0x6f8/0xbb0 drivers/tty/tty_io.c:2033 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4e6/0x1380 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3412 [inline] path_openat+0x10e4/0x4710 fs/namei.c:3529 do_filp_open+0x1a1/0x280 fs/namei.c:3559 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_compat_sys_open fs/open.c:1134 [inline] __se_compat_sys_open fs/open.c:1132 [inline] __ia32_compat_sys_open+0x79/0xb0 fs/open.c:1132 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f89a39 Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000fff1d018 EFLAGS: 00000246 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 00000000fff1d05c RCX: 0000000000127200 RDX: 0000000000000000 RSI: 00000000fff1d05c RDI: 0000000000000000 RBP: 00000000fff1d4a8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 8949: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:485 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:526 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:670 [inline] vc_allocate drivers/tty/vt/vt.c:1085 [inline] vc_allocate+0x1fc/0x760 drivers/tty/vt/vt.c:1066 con_install+0x52/0x410 drivers/tty/vt/vt.c:3229 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev drivers/tty/tty_io.c:1341 [inline] tty_init_dev+0xf7/0x460 drivers/tty/tty_io.c:1318 tty_open_by_driver drivers/tty/tty_io.c:1985 [inline] tty_open+0x4a5/0xbb0 drivers/tty/tty_io.c:2033 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4e6/0x1380 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3412 [inline] path_openat+0x10e4/0x4710 fs/namei.c:3529 do_filp_open+0x1a1/0x280 fs/namei.c:3559 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_compat_sys_open fs/open.c:1134 [inline] __se_compat_sys_open fs/open.c:1132 [inline] __ia32_compat_sys_open+0x79/0xb0 fs/open.c:1132 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 8950: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] kasan_set_free_info mm/kasan/common.c:334 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:473 kasan_slab_free+0xe/0x10 mm/kasan/common.c:482 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 vt_disallocate_all+0x2bd/0x3e0 drivers/tty/vt/vt_ioctl.c:323 vt_ioctl+0xc38/0x26d0 drivers/tty/vt/vt_ioctl.c:816 vt_compat_ioctl+0x457/0x7a0 drivers/tty/vt/vt_ioctl.c:1232 tty_compat_ioctl+0x1b0/0x420 drivers/tty/tty_io.c:2847 __do_compat_sys_ioctl fs/compat_ioctl.c:214 [inline] __se_compat_sys_ioctl fs/compat_ioctl.c:142 [inline] __ia32_compat_sys_ioctl+0x233/0x610 fs/compat_ioctl.c:142 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 The buggy address belongs to the object at ffff8880a7e49000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 512 bytes inside of 2048-byte region [ffff8880a7e49000, ffff8880a7e49800) The buggy address belongs to the page: page:ffffea00029f9240 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 raw: 00fffe0000000200 ffffea0002526a88 ffffea00027eb148 ffff8880aa400e00 raw: 0000000000000000 ffff8880a7e49000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a7e49100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7e49180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a7e49200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a7e49280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7e49300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================